We propose a new mechanism of magneto-optical Faraday and Kerr effects. Our mechanism is based on spin–orbit interaction of conducting electrons of ferromagnetic material with the electric field of the radiation. We estimate the magnitude of magneto-optical effects originated from this mechanism with the magnitude obtained in the framework of standard mechanism, based on spin–orbit scattering of the conducting electrons at the potential of crystal lattice. We discuss the possibility to distinguish this new contribution in the experiment.